This invention relates to a power saving function of a storage system, and more particularly, to power saving realized by a volume management method which focuses on a copy pair.
Recent system enlargement has been accompanied by an increase in power consumption. Thus, power saving has become increasingly important for the purpose of reducing management costs and in view of environmental problems. For a storage system, too, the power saving problem has become important. Conventionally, the storage system has had a power ON/OFF function for each disk as a power saving function, and has realized power saving by effectively utilizing the power saving function.
The effective utilization of the power saving function necessitates separation of frequently used disks from less frequently used disks. For the disk separation based on the use frequency of disks, there is a method which focuses on an operation schedule of an application host as disclosed in, for example, JP 2007-102322 A. Further, there is another method which migrates a storage area between storage systems as disclosed in, for example, JP 2008-015886 A.